The arteriovenous impulse system in total hip arthroplasty

Despite the continuing high incidence of deep vein thrombosis after total hip arthroplasty, currently available mechanical thromboprophylactic systems are not sufficiently utilised in Germany.

Duplex-sonographic measurements of the maximum venous flow velocity (V. femoralis) in 10 healthy individuals performed with a leg orientation synonymous to that during total hip arthroplasty were compared to figures obtained during an out-stretched leg position. Additionally, duplex-sonography was conducted on 9 patients intra-operatively during total hip replacement to complete the study. All investigations were executed both with and without application of the A-V Impulse System (AVIS), a mechanical thromboprophylactic procedure.

In contrast to the out-stretched leg position, a decreased venous peak flow velocity during surgery as well as in the operation-identical leg orientation was demonstrated in the absence of AVIS. However, by means of AVIS, a significant increase in the venous peak flow velocity (p < 0.01) was achieved for both situations. Additionally, an increased vessel diameter of the V. femoralis communis was observed in 75% of patients due to the leg orientation stipulated for hip replacement surgery.

The data suggest that the A-V Impulse System can effectively accelerate the venous reflux-flow during operations involving hip replacements and thus provide an early preventative therapy for deep vein thrombosis after a surgical procedure.